Pneumatic pressure respiratory vest



Jan- 20, 19 JOHN JEN-CHU CHU 2,859,537

PNEUMATIC PRESSURE RESPIRATORY VEST Filed June 14, 1957 S R E n L 3 T2 2i i lA/VE/V 727/3. JOHN J. c. CHU y M Mm Affarneys PNEUMATIC PRESSURERESPRQAIGRY VIEW John Jen-ch11 Chu, Salem, Greg.

Application June 14, 1957, Serial No. 665,83tl

2 Claims. (Cl. 128-2i) This invention relates to a new method oftreatment and to a device in the general form of a vest for assistingnatural respiration in patients suffering from certain respiratoryailments, as distinguished from pressur breathing devices for producingartificial respiration.

Many patients with chronic pulmonary diseases exhibit a tendency towarddeveloping chronic pulmonary emphysema. This condition may be describedas simply o-ver-distension of the lung tissues. In advanced stage, itcauses the patient severe shortness of breath and eventually leads toserious pulmonocardiac complications. In such condition the lungs have ahigh resting expiratory level whereby at the end of expiration theycontain an abnormally large amount of residual air which the patientcannot expel. When the lungs remain thus distended at the end ofexpiration it follows that the volume of inspiration is necessarilyreduced to a subnormal value. Such patients, therefore, experienceshallow breathing wherein the exchange of air is inadequate. At somepoint in the development of this condition, the patient finds that hecan no longer obtain enough fresh air by natural breathing and mustresort to some form of artificial aid.

The aid heretofore employed by such patients has been some kind ofpressure breathing or artificial respiratory device employing amechanical pump for forcing air into and out of the patients lungs as asupplement to the natural breathing efforts. Conventional artificialrespiratory apparatus, however, has many limitations whereby suchapparatus cannot be made available to all patients who might bebenefitted thereby. The apparatus is costly to build, its use usuallyrequires an attendant and it usually requires an electric power supply.The common and successful types of such devices are quite bulky andrequire the patient to be taken out of bed and placed bodily in theapparatus. Even portable artificial respiration devices seriouslyencumber the patient and impose severe limitations upon any activity inwhich he may wish to indulge.

It is, therefore, the general object of the present in vention toprovide a new and improved method of treatment and a relatively simpleand inexpensive device to assist the respiration of such patientswithout entailing the numerous disadvantages and limitations of theconventional artificial respiratory machines.

A further object is to provide a method and device to assist naturalrespiration rather than produce artificial respiration. v

A further object is to increase the tidal volumewithout resorting topressure breathing.

assess? Patented Jan. 20, 1959 Other objects are to provide arespiratory device of the type described which can be applied andmanipulated by the patient himself andwhich will permit the patient towalk and move about in a normal manner without imposing any limitationson any activities of which he is capable.

As a departure from the theory of operation of con ventional artificialrespiratory devices, the present invention provides an aid to naturalrespiration without employing power-operated mechanism to produce abreathing rhythm. Applicant has found that some tuberculosis patientswith advanced chronic pulmonary emphysema experience the greaterdifficulty in the expiratory stage by not expelling enough volume of airduring the respiratory cycle. This is due to the prolongedover-distension of the lungs, plus air-way obstructions, which make itdiflicult for the contraction of lungs and thoracic cage sufficiently toproduce a normal expiration. It follows, of course, that without anormal volume of expiration there cannot be a normal volume ofinspiration whereby, if the expiration can be improved, the inspiratoryeffort will be much improved.

For a reliable and more detailed explanation of the breathing problem inchronic pulmonary emphysema patients, reference is made to ChronicPulmonary Emphysema by Maurice S. Segal and M. J. Dulfano, published byGrime & Stratton, N. Y., copyright, 1953, Library of Congress CatalogCard No. 53-9299.

Based on the foregoing reasoning, the present device comprises a vestwhich is laced or otherwise fitted snugly to the patient while he is inrelaxed condition. The vest contains inflatable air bags overlying thelower part of the thoracic cage where the maximum expansion andcontraction of the thoracic cage occurs in breathing. Upon inflating theair bags in the vest, the thoracic cage and the lungs therewithin arecompressed to some extent thereby reducing the over-distension of thelungs and volume of residual air contained therein, especially at theend of the expiratory stage, and the respiratory cycle is modified to alower resting expiratory level. Contrary to what might be expected, suchflexible compression does not impair the inspiration. The patient isbenefitted by immediate relief of dyspnea and less muscular exertionduring respiration, and in many instances, the displacement volume ineach respiratory cycle is found to be increased. This is proved bypulmonary function tests, and also by observing the fact that bed-riddenpatients by using the device can get up and walk and engage in otheractivities which they had been forced to discontinue due to severedyspnea.

In most cases patients can put the vest on and adjust it withoutassistance. They may then inflate it to the pressure from time to timeas they may find desirable by experience. Thus, with the assistance ofthe present device, patients in such condition not only experience aconsiderable degree of relief but also are made ambulatory so that theycan resume a more normal life. This device does not effect a cure but itdoes make it easier for the patient to endure an incurable condition.

The invention will be better understood and additional objects andadvantages will become apparent from the following description taken inconnection with the accompanying drawings which illustrate a preferredform of the invention. It is to be understood, however, that theinvention may take other forms, and that all such 6 modifications andvariations within the scope of the appended claims which will occur topersons skilled in the art are included in the invention.

In the drawings:

Figure l is a front perspective view of the present respiratory vestapplied to a patient;

Figure 2 is a back view of the vest also applied to a patient;

Figure 3 is a cross sectional view taken on the line 33 of Figure l; and

Figure 4 is a graph illustrating tidal volume and respiratory rate of apatient with and without the present vest.

Referring specifically to the drawings, the numeral It? designates,generally, the respiratory vest of this invention, and, as seen inFigures 1 and 2, the vest is adapted to be worn on the upper trunkportion of a patient I. 1'. preferred form thereof comprises a garmentmade from a rugged and durable flexible but substantiallynon-stretchable fabric having arm openings 12 and a neck opening 34. Thevest has a slide fastener 16 at the front and has side laces 13 whichprovide a size adjustment to properly fit the vest on a patient, aproper fit being one wherein the vest fits the patient closely or snuglyat least in those areas of the rib cage which have maximum contractionand expansion during respiration.

The vest is provided at the lower portion thereof with a pair of sidepockets 20, each having a small lateral opening 21, and each supportingtherein an inflatable rubber bag 22. Pockets 20 are located inpredetermined positions so as to overlie the lower costal region in anarea extending partially in front and partially around the sides of thepatient. Preferably, the pockets 20 are formed by stitching around allfour sides of a pair of rectangular patches 19 applied to the inside ofthe vest and having sufficient fullness of material so that the pocketswill tend to bulge inwardly rather than outwardly when bags 22 areinflated. Outward expansion is restrained by hoop tension in the vestwhen the latter is securely and snugly fastened on a patient before thebags are inflated. Openings 21 are formed in the vest itself within thepocket area.

One of the air bags 22 has a pair of hoses or tubes 24 and Z5 and theother air bag has a pair of hoses or tubes 28 and 3t projecting from thepocket openings 21. The two air bags are connected together by hoses 26and 30 coupled by means of a suitable detachable coupling 32. Hose 24leads to an air pressure gauge 34 and hose 28 leads to an air bulb- 36of a well-known type capable of operating as a pump upon repeatedsqueezing thereof. Bulb se is equipped with inlet and outlet checkvalves 37 and 38 and a manual relief valve 39 which may be opened todeflate the air bags 22.

By the arrangement shown, when the bulb 36 is operated as a pump, bothbags are inflated and the pressure existing in the bags is indicated onthe pressure gauge Suitable loops 4t) and tie strings 42 are provided onthe vest for anchoring the hoses, the pressure gauge 34 and bulb 36 atconvenient locations.

As best seen in Figure 1 and as explained hereinbefore, the pockets 2t}and the inflatable air bags 22 overlie the lower costal region and, morespecifically, are preferably engageable with the rib cage at lateral orside areas and in anterior or frontal areas. Such position of the airbags is shown in the sectional view of Figure 3. With the air bagsinflated, the thoracic cage, as well as the lungs, are compressedsomewhat to reduce the abnormal distension which is characteristic ofthe patients referred to. The volume of residual air in the lungs isreduced whereby the resting expiratory level is lowered. It is foundthat such restriction greatly increases the tidal volume and greatlyreducesthe respiratory rate.

To illustrate the effectiveness of the present vest, there is shown inFigure 4 a true reproduction of a kymographic reading or graph taken ona Collins respirometer 4 (13.5 liter) showing respiration of a typicalpatient in an advanced stage of pulmonary emphysema. This patient was aman seventy years old, weighing 147 pounds and five feet eight inches inheight. The graph plots volume against time, the time being designatedby minutes and the volume being designated by liters, the graph paperrunning under the stylus from left to right at constant speed. Thevertical length of the stylus excursions measures tidal volume and theirfrequency across the graph indicates the respiratory rate. The lower endof each excursion indicates the resting expiratory level in relativescale value with respect to the other excursions.

Following the stylus markings 44 from right to left, the graphillustrates the effectiveness of the present vest in slowing down thehigh respiratory rate and in increasing the very small tidal volume.This graph comprises a continuous reading for about two minutes with nochanges made in any condition except that after a short interval the airbags 22 were inflated. The horizontal distance, designated by the letterA, represents an interval of steady breathing before inflation andillustrates the tidal volume, resting expiratory level and frequency ofrespiration with the air bags deflated. Thereupon, at the time Toperation of the hand pump was started and continued for an interval B.The desired pressure was attained and the pumping stopped at time T Thehorizontal distance on the graph designated by the letter C illustratesthe changes in these values which were then registered for one minutewith the vest inflated.

Upon comparison of the two parts A and C of the reading, it will be seenthat the respiratory rate without the assistance of the inflated bags isapproximately double and the tidal volume roughly half that observedafter inflation. With the vest inflated, the tidal volume increased from500 cc. to 900 cc. and the respiratory rate decreased from 34 to 17. Theresting expiratory level decreased from a scale value of around 5200 toaround 4800, a reduction of 400 cc. in residual volume, whichimprovement in ventilation, or air exchange, has proved to be verybeneficial to the feeling of well-being of an emphysematous patient.

' The respirometer measures the volumes of gas flowing into and out ofthe patients lungs whereby, in a continuous recording starting beforeinflation of the vest, the increase in tidal volume and reduction inresidual volume re graphically indicated in terms of volumetricquantities.

With the improvement in respiration brought about by the present vest,bedridden patients have become ambuiatory and, due to its simplicity ofoperation and ban dleability, patients may be capable of applying andsupervising the function of this respiration aid without assistance. Theair bags may be inflated to a desired pressure as indicated on the gauge34, check valve 38 holding the pressure until it is released by valve39. If desired, the gauge 34 may be omitted and the air bags merelyinflated to a pressure found most helpful to the patient.

To remove the vest, after deflating the air bags, the slide fastener 16is opened and the coupling 32 between the tubes 26 and 3t) disconnectedwhereby the vest may then be slipped over the an. a. If desired, theslide fastener may be provided at the back whereby the vest may be takenoff without disconnecting the tubes 26 and 3"). The air bags are readilyremovable from the pocket openings 21 for cleaning the vest.

Having now described my invention and in what manner the same may beused, what I claim as new and desire to protect by Letters Patent is:

l. A device for assisting natural respiration in a pulmonaryemphysematous patient comprising a flexible vest, pockets inside of saidvest in opposite lower side portions thereof, said pockets being closedat their top edges and having restricted openings at their front edgesin the outside of the vest, inflatable air bags insertable into andremovable from said pockets through said openings, and tubes from therespective bags extending through said openings and detachably connectedtogether exteriorly of the vest.

2. A device for assisting natural respiration in a pulmonaryemphysematous patient comprising a flexible vest of substantiallyinelastic fabric material, adjustment means for fitting the vest snuglyto the patient, a pair of patch pockets on the inside of said vest inthe opposite lower side portions thereof, said pockets being closed onall sides except for a restricted opening at one edge of each pocket,inflatable air bags insertable into and removable from said pocketsthrough said openings, said pockets having suflicient fullness ofmaterial to cause them to bulge inwardly instead of outwardly when theair bags are inflated in said pockets with the vest fitted on a patient,a tube interconnecting said air bags exteriorly of the vest, and meansfor inflating said air bags.

References Cited in the file of this patent UNITED STATES PATENTS

